A common major drawback of brewing apparatuses of the above type is that, when the valve is set back to the normal closed position after the beverage is dispensed, the outflow conduit fails to empty completely, and retains a certain amount of beverage which, if the brewing apparatus is not opened and used immediately to produce another beverage, settles inside the outflow conduit and results in dripping.
Moreover, if a valveless brewing apparatus is used immediately after the beverage is dispensed to produce another beverage, a suction effect is produced in the outflow conduit when the infusion chamber is opened, thus drawing the leftover beverage back into the infusion chamber.
To eliminate this drawback and completely drain the outflow conduit, it has been proposed to equip the brewing apparatus with suction means which, after the beverage is dispensed, draw the leftover beverage in the outflow conduit into a container. One example of this solution is described in US 2007/0012194, in which the suction means comprise a drain valve located downstream from the outflow conduit inlet, and which connects the outflow conduit to a drain conduit that comes out inside the container. In actual use, when outflow of the beverage is cut off by closing a needle valve interposed between the infusion chamber and the outflow conduit inlet, the drain valve opens to lower the pressure inside the outflow conduit sufficiently to draw any leftover beverage into the drain conduit and the container.
Though effective, this solution has the drawback of producing serious structural complications of the brewing apparatus, which, in addition to the manufacturing problems and expense involved, increase the overall size of the brewing apparatus, thus making it less compact and less flexible in terms of use.